Trees growing atop the Bald Mountain Granite in the southern Sierra Nevada rely on nutrients from windblown atmospheric dust — more than 50 percent — compared to nutrients provided from underlying bedrock. University of Wyoming researchers led a study that found this surprising result by measuring the isotopes of neodymium in the bedrock, soil, dust and pine needles in living trees. Using this well-constrained system, the group was able to combine worldwide data to show that this phenomenon is not limited to the Sierra Nevada, and that foreign dust likely fertilizes plants in many locations worldwide. “Trees in the Sierra Nevada are using the dust for nutrients,” says Cliff Riebe, an associate professor in UW’s Department of Geology and Geophysics. “This is a novel finding.”